Skip to main content

What is active data guard and How to enable stanby database is in read-only mode (Active standby)

What is active data guard and How to enable stanby database is in read-only mode (Active standby)??

If trying open the standby database in read only mode will get the below error.

SQL> ALTER DATABASE OPEN READ ONLY;
ALTER DATABASE OPEN READ ONLY
*
ERROR at line 1:
ORA-10456: cannot open standby database; media recovery session may be in progress.

1. First we need turf off the log apply process on the standby database. Using the below.

DGMGRL> edit database <stdby_dbname> set state=apply-off;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

SQL> ALTER DATABASE OPEN READ ONLY;
SQL>Select name, open_mode, switchover_status, database_role from v$database;

Start apply process using Broker (OR) Manually in standby database.

DGMGRL> edit database <stdby_dbname> set state=apply-on;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

To disable the active data guard, the steps are the same:

1. DGMGRL> edit database stdby set state=apply-off; (OR) 
   SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
2. Shutdown the stdby database;
3. Startup mount the stdby database
4. DGMGRL> edit database stdby set state=apply-on; (OR) 
    SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

Labels:

Comments

Post a Comment

Popular posts from this blog

ORA-39014: One or more workers have prematurely exited.ORA-00018: maximum number of sessions exceeded

ERROR: I was Performing a full database import and during the import I faced the below error. ORA-39014: One or more workers have prematurely exited. ORA-39029: worker 6 with process name "DW07" prematurely terminated ORA-31672: Worker process DW07 died unexpectedly. Job "SYSTEM"."SYS_IMPORT_FULL_04" stopped due to fatal error at 00:59:40 ORA-39014: One or more workers have prematurely exited. SOLUTION:  Run the import with fewer parallel processes, like PARALLEL=2 instead of 8. I was able to run the import successfully. NOTE 1: This errors occurs when there are less session allocation in the database. check the session,process parameters and increase them accordingly. To avoid such errors again. NOTE 2 : Note: Increasing processes parameter increases the amount of shared memory that needs to be reserved & the OS must be configured to support the larger amount of shared memory. So here we first need to increase the Memory & SG...
Post a Comment
Read more

ORA-01143: cannot disable media recovery - file 1 needs media recovery

I got a request from the client - To flashback the database to the existing restore point & disable flashback and archive log mode for database UATB. Here I came a cross error - ORA-01143. I followed the below steps. 1. SQL> select name from v$database; NAME ------------ UATB 2. SQL> SELECT NAME FROM V$RESTORE_POINT WHERE GUARANTEE_FLASHBACK_DATABASE='YES' ORDER BY TIME; NAME --------- UATB_COPY Here I'm going to restore the database to the above restore point. NOTE: The flashback database restore has to be done in MOUNT stage of the database. SQL> select name from v$database; NAME --------- UATB SQL> shut immediate; Database closed. Database dismounted. ORACLE instance shut down. SQL> startup mount ORACLE instance started. Total System Global Area  612368384 bytes Fixed Size                  1250428 bytes Variable Size             167775108 bytes ...
2 comments
Read more